Process and apparatus for the manufacture of incandescent mantles for inverted incandescent lighting



L. SEVERIN.

PROCESS AND APPARATUS FOR THE MANUFACTURE OF INCANDESCENT MANTLE S FOR INVERTED INCANDESCENT LIGHTING.

APPLICATION man APRJB, i914.

Patented Apr. 4, 1922.

3 SHH. [3-SHEET 1- L. SEV-ERIN.

PROCESS AND APPARATUS FOR THE MANUFACTURE OF INCANDESCENT MANTLES FOR INVERTED INCANDESCENT LIGHTING.

-APPLICATION FILED APR- 6,1914.

Patented Apr. 4, 1922.

3 SHLHS-SHEET 2.

Fig.6

Fig.5

[/i in 05505 2 L1 SEVERIN.

PROCESS AND APPARATUS FORTHE MANUFACTURE OF INCANDESCENT MANTLES FOR INVERTED INCANDESCENT LIGHTING.

YAPPLICATION man APR. 6, 1914.

1,411,459. V Patented .4 22.

UNITED STATES PATENT OFFICE.

LUDWIG- SEVER-IN, OF I-IAGEN-DELSTERN, GERMANY.

PROCESS AND APPARATUS FOR- THE MANUFACTURE OF INGANDESCENT MANTLES I FOR INVERTED INCANDESCENT LIGHTING.

Specification of Letters Patent.

Patented Apr. 4, 1922.

Application filed April 6, 1914. Serial No. 829,922.

(GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH 3, 1921, 41 STAT. L, 1313.)

To all whom it may concern:

Be it known that I, LUDWIG SEVERIN, a subject of the German Emperor, residing at Hagen-Delstern, Prussia, Germany, have in vented certain new and useful Improvements in Processes and Apparatus for the ill-auufacture of Incandescent Mantles for Inverted Incandescent Lighting, of which the following is a'specification.

The object of the present invention is to simplify the production, on a large scale, of incandescent mantles, provided with 'a supporting ring of magnesia or the like, for inverted incandescent lighting.

For this purpose, according to my invention, the process is as follows. The piece of material or blank or fabric, which has already been impregnated, is drawn by means ot a mandrel'into a corresponding die or mould and converted into the desired bag-shape or cup shape having an elongated approximately cylindrical body and a convex bottom. It is then connected with the supporting ring, which is fitted in the opening of the bag, by means of thread which is wound round on the outside, and is finally withdrawn from the die by means of said ring.

In carrying out the above process, one may either proceed as follows. After the shaping. of the piece oi material by means of a mandrel of the same diameter as the incandescent mantle, first Withdraw the mandrel and then introduce the supporting ring into the opening of the bag, in order to connect both parts by means of a thread wound round them on the outside, or, by using a mandrel of smaller diameter one may carry out the process in such a way that in shaping the piece of material the mandrel passes through the supporting ring and the material is drawn through the small annular space between the edges of the die and of the supporting ring and the connection takes place on the egress side of the die. As in this latter modification of the process the diameter of the mandrel must be considerably smaller than that of the mantle, in some circumstances special precautions may also be necessary, in order to prevent the formation of folds during the shaping of the incandescent mantle. These precautions can, for example, consist in blowing out the mantle by means of a current of air while it is being shaped, or the head of the mandrel may be subsequentlv enlarged' in any suitable manner. U

The material from which the incandescent mantle is to be formed may advantageously consist of a knitted fabric, in some cases however, a woven or braided fabric may be used, and a material of which the size of the mesh is larger at the edges than in the middle may conveniently be employed. It is thus eifected that during the shaping of the incandescent mantle a too great accumulation of material or formation of folds at the suspension edge is avoided. It is suitable to choose the width of the mesh of the material to be so much greater at the edges that, during its conversion in to the desired bag-shape only a small accumulation of material occurs in comparison with the bottom of the mantle and thus the suspension edge, on which most depends, is advantageously strengthened, without how ever the formation of folds or a too greataccumulation of material taking place The shaping of the incandescent mantle may be done equally well when the piece of material is in a dry as when in a damp condition. The following is however an advert tageous method. The material. is introduced into the die in a damp condition, is dried in the die and then withd sun from it. In

this way a particularly good and dilrable' form of mantle is obtained. v

In every case one obtains m a simple mam ner a finished impregnated incandescent mantle connected to its supporting ring.

Several methods of carrying out the process are illustrated, by way of example, in the accompanying drawings together with apparatus suitable for use in each case. Figs. 1% illustrate the process when using a mandrel ofthe same diameter as the mean descent mantle and employing a cylindrical socket as the die.

Figs, 5-7 illustrate the same process when using a ring as the the. a

Fig. 8 shows a piece of material with meshes increasing in size towards the edges. suitable for the manufacture of incandescent mantles.

Figs. '9 and 10 illustrate the process when using a rigid mandrel which can be passed through the supporting ring.

Figs. ll and 12 show the process when using a mandrel of variable diameter.

In Figs. 1-l a. is a cylindrical die 'or socket, the upper opening of which forms the shaping aperture for producing the in candescent mantle, and I) is a mandrel fitting into this opening. In manufacturing the mantle a flat or nearly flat piece of material 0, impregnated withthe luminous or incandescent medium, and of suitable size is placed on the die a as shown in Fig. 1, in either a dry or a damp condition. The material consists preferably of knitted fabric but may in some cases be of. woven or braided fabric. Then, as may bc'seen from Fig. 2, the material is pressed into the cylindrlcal die by means of the mandrel b, and edges 0 projecting upwards are drawn tight in the direction of and also at right angles to the mandrel, so that the meshes of the knitted fabric lying around the mandrel are drawn lengthways and'thereby any lateral folds, if present, are removed. After the material has already thus been brought d, to which the mantle is subsequently fastened, isv set in place in the upper edge of the mantle, as is shown in Fig. 3. Then the mantle is fastened to the magnesia ring by means of a thread f of asbestos or other heat resisting material, which wound round it, and is drawn out of the mould or socket a by means of said ring. After the mantle has been withdrawn from the die its sides arch outwards somewhat in consequence of their elasticity, so that the mantle automatically assumes by radial expansion and longitudinal contraction the convex cup shape desired, as shown in Fig. 4 for the following incineration and hardening and retains this shape.

When using materials in a damp condition they are subjected to a drying process after shaping by which means an increased permanency of shape is given to the incandescent mantle. 7

The mode of carrying out the process which is illustrated in 5--7 differs from that described above firstly in that a simple ring is used instead of the cylindrical. die shown in Figs. i=3. This ring a may suit ably consist of indie-rubber 01' other similar elastic material and the process can be suitably carried out in the following manner. a

stripped off together with the ring (Fig. 6).

its position on the base it by means of a central mandrel g which projects into the opening of the ring.

Instead of the rubber ring a, in some cases a simple thread of ramie fibre or other material may be used. The advantage of this is that the special removal of the ring is unnecessary because in the subsequent i11- cineration thethread is simply consumed as well.

Fig. 8 shows the peculiar mesh arrange ment of a piece of material. It can be distinctly seen that the width of the meshes becomes considerably largerfrom the centre of the material towards the outside. Thus too great an accumulation of material. at the upper edge of the incandescent mantle is avoided.

In the processes illustrated in Figs 9 and 10 the apparatus employed may suitably consist of a fixed shaping piece i having a recess is in its'upper end, in which the supporting ring d is placed in an inverted position',v that is, with its feet downwards. Immediately above the piece 2' a plate at having a circular opening is arranged. Thisplate can either be fitted? from" above over the edge of the support d or may advantageously consist of two halves which can slide or be adjusted laterally, and forms the shaping aperture. The mandrel n is vertically guided in the central bore of the'shaping piece '5 and its diameter is such that it can pass through the supporting ring.

In manufacturing the mantle the supporting ring (Z is first set in the upper recess is in the shaping piece i with its feet downwards and the material a laid over it as shown in Fig. 9. Thenthe two halves of the shaping plate m. are moved close to-' gether laterally and the mandrel n is moved upwards, so'that the piece of material 0 is drawn between the edge of the shapingpiece shape, but this results during the usual suhsoquent treatment (incineration, hardening and the like) of its own accord. A good shape can however be at once obtained if another die or socket 0 as shown by dotted lines in Fig. 10, is placed over the mantle and compressed air blown in from below through piping not shown in the drawing, for example, by constructing the mandrel itself of hollow form, so that the mantle is blown to the shape desired.

The arrangement of this second die has further the great advantage that there remains a gap 1; between the die 0 and the ring plate m on a level with the connection groove of the magnesia ring. This gap serves as a guide-passage for the introduction of the fastening thread and thus the actual fastening is cmlsidcrabl y facilitated and the working is accelerated.

Instead of a mandrel of unalterable diameter in some cases one employs a mandrel of which the upper part can be extended in a suitable manner after being introduced into the maptle.

In the example illustrated in Figs. 11 and 12 the mandrel itself is formed from. a simple envelope 1* which is connected with a pipe 8 for the inflow and outflow of the filling medium and provided with a net-work 15 which when expanded possesses exactly the desired shape. This alterable mandrel can either be movable longitudinally as shown in Figs. 9 and 1,0 or may be fixed as shown in Figs. ll and 12. In the latter ease as shown in Fig. 11 the magnesia ring is placed over the mandrel which is at first only slightly extended, and the mandrel is then blown up to the correct shape (Fig. l2). The piece of material is then laid over it. smoothed out and bound with the thread and fastened. Finally the air is released from the extended mandrel so that this rollapses and the finished mantle can be removed from above. I

The mantles manufactured by the process according to the invention can then be sub jected to the usual further treatment, i. e. incinerated, shaped and hardened or can be put on the market as impregnated bodies.

lVhat I claim as my invention and desire to secure by Letters Patent is:-

l The process of making inverted gas mantles comprising molding a piece of suitably impregnated material. approximately into the form of a cup between internal and external. means. permitting it to take more completely by expansion the form of a cup, aiding such expansion by injection of air and tying the rim of such cup to a carrier ring.

2. A gas mantle blank of circular form consisting of a fabric having meshes at and near its edge considerably coarser than those in the middle.

In apparatus for making incandescent gas mantles from. suitably impregnated.

pieces of fabric, the combination of a cuplike die for receiving the piece of fabric. a carrier ring arranged to press the inner part of said fabric into said die and a mandrel adapted to be inserted into said ring and die for drawing the fabric between the latter two parts, the said ring being adapt-- ed to have the said fabric tied thereto before withdrawing the mantle from the die.

4:. In apparatus for making incandescent gas mantles from suitable impregnated pieces of fabric, the combination of a cuplike die for receiving the same, a carrier ring arranged to press the inner part of said fabric into said die, an expansible mandrel adapted to be inserted into said ring and die for drawing the fabric between the latter two parts and means for expanding the mandrel, the said ring being adapted to have the said fabric tied thereto before removal from the die.

5. In apparatus for making incandescent gas mantles from suitable impregnated. pieces of fabric, the combination of a cuplike die for receiving the piece of fabric, a carrier ring arranged to press the inner part of said fabric into said die, a mandrel adapted to be inserted into said ring and die to draw the fabric between the latter two parts and means for blowing air into the fabric to expand the same into the die the said ring being adapted to be tied to the said fabric before withdrawing the mantle from the die.

6. In apparatus for making incandescent mantles from suitably impregnated pieces of fabric. the combination of a cup like die for receiving the piece of fabric with an expansible mandrel adapted to enter said die, a carrier ring adapted to pass over said mandrel. while the latter is in a contracted state and means for expanding said mandrel after the ring has thus passed over it, these parts being adapted to have the fabric pressed snugly down on said mandrel and ring and tied to the latter before contract ing said mandrel. and withdrawing the mantle.

7 In apparatus for making incandescent gas mantles from suitable impregnated pieces of fabric, the combination of a die having a form corresponding to that of the mantle and. expanding means adapted to pass through the carrier ring of the mantle, for pressing the fabric snugly into said die.

8. In apparatus for making incandescent gas mantles from suitably impregnated pieces of fabric, the combination of a die having a. form corresponding to that of the mantle and a mandrel, capable of being blown out and adapted to pass through the carrier ring of the mantle, for pressing the fabric snugly into said die.

9. In apparatus for making incandescent gas mantles from suitably impregnated pieces of fabric, the combination of a' In testimony whereof, I have signed my holder for the earner mug, and a mandrel, name to thls speolfioatlon 1n the presence of capable of belng blown out mounted 1n sald two subscrihln r witnesses.

holder and adopted to pass through said LU \VIG SEVERIN. [i s.] ring, and a net surrounding said mandrel Witnesses: e and adapted to give the letter, when blown HELEN NUFER,

out, the shape of the mantle. ALBERT LTUFEII. 

